165623404 has 12 divisors (see below), whose sum is σ = 293923728. Its totient is φ = 81645200.

The previous prime is 165623389. The next prime is 165623407. The reversal of 165623404 is 404326561.

It is a super-2 number, since 2×165623404² = 54862223905094432, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (165623407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 291307 + ... + 291874.

It is an arithmetic number, because the mean of its divisors is an integer number (24493644).

Almost surely, 2^165623404 is an apocalyptic number.

It is an amenable number.

165623404 is a deficient number, since it is larger than the sum of its proper divisors (128300324).

165623404 is a wasteful number, since it uses less digits than its factorization.

165623404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 583256 (or 583254 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 31.

The square root of 165623404 is about 12869.4756691949. The cubic root of 165623404 is about 549.1705447684.

Adding to 165623404 its reverse (404326561), we get a palindrome (569949965).

The spelling of 165623404 in words is "one hundred sixty-five million, six hundred twenty-three thousand, four hundred four".